scholarly journals Spectrophotometric Determination of Praseodymium by 1,4- Dihydroxyanthraquinone after its Selective Separation from Rosetta Monazite Rare Earth Concentrate by Solvent Extraction

2015 ◽  
Vol 1 (2) ◽  
Author(s):  
Abdel Fattah N. A   -      a Sadeek A. S    -      b Ali B.
Keyword(s):  
Rare Earth ◽  
Good Accuracy ◽  
Molar Absorptivity ◽  
Selective Separation ◽  
Air Oxidation ◽  
Reaction Conditions ◽  
Relative Standard ◽  
Colour Development ◽  
Sensitive Spectrophotometric Method

A rare earths concentrate of Rosetta monazite assays about 44, 23, 16.94 and 5.91 % for Ce, La, Nd and Pr respectively. Separation of cerium by air oxidation at 200oC. Selective separation of Pr by D2EHPA at pH1 followed by a sensitive spectrophotometric method which described for the determination of praseodymium (Pr) with l,4-dihydroxyanthraquinone . The calibration curve was linear from   0.1 to 12 µgml -1 praseodymium. The influences of various parameters and reaction conditions for maximum colour development were investigated. The relative standard deviation for determination of 1 µgml-1 praseodymium has found to be 1.3 after 5 repeated determinations; percent error 5.02%, molar absorptivity (ε) was 1.23x106M-1 cm-1and detection limit was 0.1µgml-1. The method for determination of praseodymium showed good accuracy and selectivity.

scholarly journals A sensitive spectrophotometric determination of tadalafil in pharmaceutical preparations and industrial wastewater samples

2013 ◽  
Vol 10 (3) ◽  
pp. 1005-1013 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Standard Deviation ◽  
Industrial Wastewater ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Average Recovery ◽  
Relative Standard ◽  
Wastewater Samples ◽  
Sensitive Spectrophotometric Method

A simple, accurate, precise, rapid, economical and a high sensitive spectrophotometric method has been developed for the determination of tadalafil in pharmaceutical preparations and industrial wastewater samples, which shows a maximum absorbance at 204 nm in 1:1 ethanol-water. Beer's law was obeyed in the range of 1-7?g/ mL ,with molar absorptivity and Sandell ? s sensitivity of 0.783x105l/mol.cm and 4.97 ng/cm2respectively, relative standard deviation of the method was less than 1.7%, and accuracy (average recovery %) was 100 ± 0. 13. The limits of detection and quantitation are 0.18 and 0.54 µg .ml-1, respectively. The method was successfully applied to the determination of tadalafil in some pharmaceutical formulations (tablets) and industrial wastewater samples. The proposed method was validated by sensitivity and precision which proves suitability for the routine analysis of tadalafil in true samples.

scholarly journals Spectrophotometric Method for Determination of Paraquat in Food and Biological Samples

1997 ◽  
Vol 80 (2) ◽  
pp. 388-391 ◽  
Author(s):  
Ritu Kesari ◽  
Manish Rai ◽  
Vinay Kumar Gupta
Keyword(s):  
Standard Deviation ◽  
Metal Ions ◽  
Relative Standard Deviation ◽  
Alkaline Medium ◽  
Spectrophotometric Method ◽  
Biological Samples ◽  
Molar Absorptivity ◽  
Relative Standard ◽  
Sensitive Spectrophotometric Method

Abstract A sensitive spectrophotometric method was developed for determination of paraquat, a widely used herbicide. Paraquat was reduced with glucose in an alkaline medium, and the blue radical ion obtained was measured at 600 nm. Beer’s law was obeyed at 0.1–1.2 ppm paraquat. The molar absorptivity was 1.26 × 105 L mol-1 cm-1. The standard deviation and relative standard deviation were ± 0.007 and 2.0%, respectively, for 5 μg paraquat/10 mL analyzed over 7 days. The method was free from interference by other commonly used pesticides and metal ions. The method may be used to the determine paraquat in plants, fruits, grains, water, blood, and urine.

Spectrophotometric Determination of Boron in Dates of Some Cultivars Grown in Saudi Arabia

1993 ◽  
Vol 76 (3) ◽  
pp. 601-603 ◽  
Author(s):  
A A Al-Warthan ◽  
S S Al-Showiman ◽  
S A Al-Tamrah ◽  
A A BaOsman
Keyword(s):  
Saudi Arabia ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Spectrophotometric Determination ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Relative Standard ◽  
Sensitive Spectrophotometric Method

Abstract The formation of a red complex between boron and the quinalizarin reagent was investigated and used as the basis for a simple and sensitive spectrophotometric method for boron in date cultivars. At 620 nm, the absorbance was linear (r= 0.999) over the 0.25-2.5 μg/mL concentration range. The molar absorptivity was found to be 2.23 x 103mol-1cm-1 and the relative standard deviation for 10 replicates (1.0 μg/mL) was 0.97%.

Validated Spectrophotometric Determination of Rizatriptan Benzoate in Pharmaceutical Formulations using Alizarin Derivatives

2019 ◽  
Vol 10 (01) ◽  
Author(s):  
El Sheikh R ◽  
Hassan W. S. ◽  
Gouda A. A. ◽  
Al OwairdhiA. ◽  
Al Hassani K K H
Keyword(s):  
Standard Addition ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Optimum Conditions ◽  
Reaction Conditions ◽  
Alizarin Red ◽  
Rizatriptan Benzoate ◽  
Spectrophotometric Methods ◽  
Relative Standard

Two simple, sensitive, accurate, precise and economical spectrophotometric methods have been developed and validated for the determination of rizatriptan benzoate (RZT) in pure form and pharmaceutical formulations. These methods were based on the formation of charge transfer complex between RZT as n-electron donor and alizarin red S (ARS) or quinalizarin (Quinz) as π-acceptor in methanol to form highly colored chromogens which showed an absorption maximum at 532 and 574 nm using ARS and Quinz, respectively. The optimization of the reaction conditions such as the type of solvent, reagent concentration and reaction time were investigated. Under the optimum conditions, Beer’s law is obeyed in the concentration ranges 1.0-16 and 2.0-20 g mL-1 using ARS and Quinz, respectively with good correlation coefficient (r2 ≥ 0.9996) and with a relative standard deviation (RSD% ≤ 1.16). The molar absorptivity, Sandell sensitivity, detection and quantification limits were also calculated. The methods were successfully applied to the determination of RZT in its pharmaceutical formulations and the validity assesses by applying the standard addition technique. Results obtained by the proposed methods for the pure RZT and commercial tablets agreed well with those obtained by the reported method.

scholarly journals Direct Spectrophotometric Determination of Glimepiride in Pure Form And Pharmaceutical Formulations Using Bromocresol Purple

2018 ◽  
Vol 15 (2) ◽  
pp. 6186-6198
Author(s):  
Abdul Aziz Ramadan ◽  
Souad Zeino
Keyword(s):  
Limit Of Detection ◽  
Reference Method ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Bromocresol Purple ◽  
Reaction Conditions ◽  
Reagent Blank ◽  
Limit Of Quantification ◽  
Relative Standard

A simple, direct and accurate spectrophotometric method has been developed for the determination of Glimepiride (GLM) in pure and pharmaceutical formulations by complex formation with bromocresol purple (BCP). The method involves the formation of a yellow ion-pair complex between BCP with glimepiride at pH<3,8; after reacting GLM with Na2CO3 to give C24H33N4H+O5NaS which is extracted by chloroform. The formed complex [GLM]:[ BCP] was measured at lmax 418 nm against the reagent blank prepared in the same manner. Variables were studied in order to optimize the reaction conditions. Molar absorptivity (e) for complex was  20600  L.mol-1.cm-1. Beer’s law was obeyed in the concentration range of  1.226 – 46.608   mg.mL-1 in present of 5.0x10-4 mol/l of BCP with good correlation coefficient (R2= 0.9997). The relative standard deviation did not exceed 3.6%. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.15 and 0.46 mg.mL-1, respectively. The proposed method was validated for specificity, linearity, precision and accuracy, repeatability, sensitivity (LOD and LOQ)  and robustness. The developed method is applicable for the determination of GLM in  pure and different dosage forms with average assay of 98.8 to 102.0% and the results are in good agreement with those obtained by the  RP-HPLC reference method.  

The fluorimetric determination of cerium and terbium

1989 ◽  
Vol 54 (3) ◽  
pp. 616-621 ◽  
Author(s):  
Záviš Holzbecher
Keyword(s):  
Rare Earth ◽  
Detection Limit ◽  
Rare Earth Elements ◽  
Fluorimetric Determination ◽  
Fluorescence Maximum ◽  
Relative Standard ◽  
And Shifts ◽  
Hcl Medium ◽  
Fold Excess

It has been found that phosphoric acid decreases the first excitation maximum of Ce(III) at 256 nm, increases the second excitation maximum at 297 nm and shifts the fluorescence maximum from 350 to 346 nm. Under optimum conditions, with λexc = 297 nm and λem = 346 nm, Ce(III) can be determined fluorimetrically with a detection limit of 1.2 ng ml-1 in 12M-H3PO4 medium. No interference was observed from a 20-200 fold excess of HCl, H2SO4, Na, K, NH4+, Al and the rare earth elements. HNO3 interferes and Ce(IV) and Fe(III) interfere strongly. It follows from the stereofluorograms of Ce and Tb that the spectra of the two elements are practically independent. The detection limit for Tb(III) in 0.02-2.5M-H2SO4 medium for λexc = 222 nm and λem = 494 nm is 33 ng ml-1. No interference was observed from a 5-20 fold excess of Al3+ and the other rare earth elements. The determination is slightly less sensitive in H3PO4 or HCl medium. The relative standard deviation of the measurement for 10 ng ml-1 Ce(III) or 50 ng ml-1 Tb(III) is about 3%.

VALIDATED RP-HPLC AND UV-SPECTROSCOPY METHODS FOR THE ESTIMATION OF DAPAGLIFLOZIN IN BULK AND IN TABLETS

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (03) ◽  
pp. 44-51
Author(s):  
B. Sabbagh ◽  
B. V. S. Lokesh ◽  
G. A. Akouwah ◽  
Keyword(s):  
Good Accuracy ◽  
Uv Spectroscopy ◽  
Linear Regression Analysis ◽  
Molar Absorptivity ◽  
Hplc Method ◽  
Rp Hplc ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Uv Visible

Two methods were developed for the determination of dapagliflozin (DAPA) in pure form and in tablets. The procedure utilized was UV-Visible Spectroscopy and RP-HPLC with PDA detector to quantify DAPA in bulk and tablets. The sensitive linear range was identified for both methods within 0.5-5.0μg/mL. The linear regression analysis was identified for both methods with correlation coefficient(r)>0.99. The LOD and LOQ values were found to be 0.05 μg/mL and 0.5 μg/mL for the method by UV-Spectroscopy. The molar absorptivity (ε) was calculated as 1.27 X 105 L.mol-1cm-1. The RP-HPLC method produced LOD and LOQ values of 1.0 ng/mL and 0.5 μg/mL. Both methods were simple, precise, reproducible to quantify the amount of unknown in bulk as well as in tablets and estimated accurately within the range of 100.0±0.5%. Statistical analysis was performed on the data obtained. There was no significant difference between the developed and reported methods with p>0.05. Both methods can be applied for routine analysis of DAPA in bulk and tablets with good accuracy and precision.

scholarly journals Indirect spectrophotometric determination of gentamicin and vancomycin antibiotics based on their oxidation by potassium permanganate

2006 ◽  
Vol 4 (4) ◽  
pp. 708-722 ◽  
Author(s):  
Akram El-Didamony ◽  
Alaa Amin ◽  
Ahmed Ghoneim ◽  
Ayman Telebany
Keyword(s):  
Acid Medium ◽  
Potassium Permanganate ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Reaction Conditions ◽  
Subsequent Determination ◽  
Optimum Reaction ◽  
Acid Orange Ii ◽  
Sulphuric Acid Medium

AbstractFour simple, accurate, sensitive and economical procedures (A–D) for the estimation of gentamicin sulphate and vancomycin hydrochloride, both in pure form and in pharmaceutical formulations have been developed. The methods are based on the oxidation of the studied drugs by a known excess of potassium permanganate in sulphuric acid medium and subsequent determination of unreacted oxidant by reacting it with amaranth dye (method A), acid orange II (method B), indigocarmine (method C) and methylene blue (method D), in the same acid medium at a suitable λmax=521, 485, 610 and 664 nm, respectively. The reacted oxidant corresponds to the drug content. Regression analysis of Beer-Lambert plots showed good correlations in the concentration ranges 4–8, 3–8, 4–9 and 5–9 µg ml−1 with gentamicin and 4–8, 1.5–4, 1.5–4 and 3.5–5.5 µg ml−1 with vancomycin for methods A, B, C, and D, respectively. The molar absorptivity, sandell sensitivity, detection and quantification limits were calculated. The stoichiometric ratios for the cited drugs were studied. The optimum reaction conditions and other analytical parameters were evaluated. The influence of the substance commonly employed as excipients with these drugs were studied. The proposed methods were applied to the determination of these drugs in pharmaceutical formulations. The results have demonstrated that the methods are equally accurate and reproducible as the official methods.

scholarly journals Simple Spectrophotometric Method for Determination of Paroxetine in Tablets Using 1,2-Naphthoquinone-4-Sulphonate as a Chromogenic Reagent

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Ibrahim A. Darwish ◽  
Heba H. Abdine ◽  
Sawsan M. Amer ◽  
Lama I. Al-Rayes
Keyword(s):  
Spectrophotometric Method ◽  
Correlation Coefficients ◽  
Molar Absorptivity ◽  
Official Method ◽  
Calibration Data ◽  
Pharmaceutical Tablets ◽  
Relative Standard ◽  
Label Claim ◽  
Colored Product

Simple and rapid spectrophotometric method has been developed and validated for the determination of paroxetine (PRX) in tablets. The proposed method was based on nucleophilic substitution reaction of PRX with 1,2-naphthoquinone-4-sulphonate (NQS) in an alkaline medium to form an orange-colored product of maximum absorption peak () at 488 nm. The stoichiometry and kinetics of the reaction were studied, and the reaction mechanism was postulated. Under the optimized reaction conditions, Beer's law correlating the absorbance (A) with PRX concentration (C) was obeyed in the range of 1–8 g . The regression equation for the calibration data was: A = 0.0031 + 0.1609 C, with good correlation coefficients (0.9992). The molar absorptivity () was L  1 . The limits of detection and quantitation were 0.3 and 0.8 g , respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 2%. The proposed method was successfully applied to the determination of PRX in its pharmaceutical tablets with good accuracy and precisions; the label claim percentage was %. The results obtained by the proposed method were comparable with those obtained by the official method.

scholarly journals Determination of Nickel in End-Fitting of Spoolable Reinforced Plastic Line Pipe

2018 ◽  
Vol 142 ◽  
pp. 01002
Author(s):  
Xiaodong Shao
Keyword(s):  
Ammonium Persulfate ◽  
Reaction Conditions ◽  
Line Pipe ◽  
Acid Gas ◽  
Determination Of Nickel ◽  
Reinforced Plastic ◽  
Relative Standard ◽  
Optimum Reaction ◽  
Fitting In

Spoolable reinforced plastic line pipe will be widely used in the exploitation of acid gas and oil wells. End-fitting is a mechanical device that forms the transition from the spoolable reinforced plastic line pipe to the connector. It was well known that nickel was an important element in the end-fitting. In this paper, a novel spectrophotometric method was described for determination of nickel in the end-fitting of spoolable reinforced plastic line pipe. The method was based on the color reaction between nickel and dimethylglyoxime, which was favored in an alkaline medium, producing a red compound in the presence of ammonium persulfate as an oxidant. Under the optimum reaction conditions the absorption value was proportional to the concentration of nickel in the range of 0.080~0.50% (R2 = 0.9999), and the relative standard deviation was less than 3.0% (n=5). The proposed method was applied successfully to determine nickel in end-fitting of spoolable reinforced plastic line pipe.

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